Michael Adkins II rushed for a game-high 90 yards and two first-half touchdowns to lead the Buffaloes (0-1). Diego Gonzalez, who made a pair of field goals in the loss, accounted for the rest of the scoring.

Sanchez converted field goals of 27 and 34 yards for Hawaii.

Colorado went three-and-out on its opening drive, but Alex Kinney's punt was blocked by Hawaii's Keelan Ewaliko, who also recovered the ball at the Colorado 16-yard line.

Three plays later, Wittek hit Pedroza for an 11-yard touchdown pass. The same two hooked up on the two-point conversion to give the Rainbow Warriors an early 8-0 lead.

The Buffaloes got on the board at the 9:21 mark of the second quarter on a 5-yard run by Adkins. The play was set-up by an interception by defensive end Derek McCartney, who picked off Wittek near the line of scrimmage and returned it 33 yards to the Hawaii 17. Gonzalez tacked on the extra point.

Hawaii answered quickly when Wittek hit Kemp on a short completion along the left hash mark. Kemp broke a tackle near the Colorado 40 en route to the 79-yard touchdown play - the team's longest since 2011.

Colorado again pulled within a point at 15-14 on a 3-yard touchdown run from Adkins that capped a nine-play, 57-yard drive with 4:47 left in the first half.

Later in the quarter, the Rainbow Warriors capitalized on a turnover when Sanchez hit a 27-yard field goal on the final play of the first half. The drive started at their own 42 after Lance Williams forced a fumble by Christian Powell, which was recovered by Marrell Jackson.

Hawaii held an 18-14 lead at the intermission.

Gonzalez's 40-yard field goal early in the third quarter cut the Hawaii lead to 18-17.

Wittek's third touchdown pass, a 1-yarder to Bernard, came late in the third quarter and Sanchez's 34-yard field goal early in the fourth stretched the Rainbow Warriors' lead back to 28-17.

Colorado again got within a score with 3:48 to play on another Gonzalez field goal and had a chance to tie it on its final possession. It drove to the Hawaii 8 in the closing seconds, but failed to get off a final play.

Wittek, a 6-foot-4, 240-pound senior, sat out last season because of NCAA regulations after transferring from USC.

Colorado wide receiver Nelson Spruce, a First Team Preseason All-Pac-12 selection, finished with eight receptions for 69 yards. Quarterback Sefo Liufau threw for 158 yards on 23-of-40 passing and rushed for 81 yards on 18 carries. He was intercepted once.

Hawaii avenged a 21-12 double-overtime loss at Colorado last year and now leads the all-time series, which dates back to 1925, 3-2. All three wins have come in Honolulu.

The Buffaloes, who are now 77-44-5 all-time in season openers, have lost their last nine games. Their last victory was against Hawaii on Sept. 20 of last year. They were picked to sixth (last) in the Preseason Pac-12 Media Poll.

The Rainbow Warriors, who were picked to finish fifth in the West Division in the Preseason Mountain West Media Poll, improved to 59-35-5 all-time in season openers. They have opened the season against a Pac-12 opponent the last six years and are now 30-58 all-time against current members of the Pac-12.

Colorado and Hawaii are the only two FBS teams that are playing 13 consecutive weeks over the 2015 season.